import React from 'react';
import ReactDOM from 'react-dom/client';
import './index.css';

// class Square extends React.Component {
//
//     render() {
//         return (
//             <button
//                 className="square"
//                 onClick={() => {
//                     // this.setState({
//                     //     value: 'x'
//                     // })
//                     this.props.onClick()
//                 }}>
//                 {this.props.value}
//             </button>
//         );
//     }
// }

function Square(props) {
    return (
        <button
            className="square"
            onClick={props.onClick}
        >
            {props.value}
        </button>
    );
}

class Board extends React.Component {
    // constructor(props) {
    //     super(props);
    //     this.state = {
    //         squares: Array(9).fill(null),
    //         xIsNext: true,
    //     }
    // }

    // handleClick(i) {
    //     const squares = this.state.squares.slice();
    //     if (calculateWinner(squares) || squares[i]) {
    //         return
    //     }
    //     squares[i] = this.state.xIsNext ? 'x' : 'o'
    //     this.setState({squares, xIsNext: !this.state.xIsNext})
    // }

    renderSquare(i) {
        return (
            <Square
                value={this.props.squares[i]}
                onClick={() => {
                    // return this.handleClick(i)
                    this.props.onClick(i)
                }}
            />
        );
    }

    render() {
        // const winner = calculateWinner(this.state.squares)
        // let status;
        // if (winner) {
        //     status = 'Winner: ' + winner
        // } else {
        //     status = `Next player: ${this.state.xIsNext ? 'x' : 'o'}`
        // }

        return (
            <div>
                {/*<div className="status">{status}</div>*/}
                <div className="board-row">
                    {this.renderSquare(0)}
                    {this.renderSquare(1)}
                    {this.renderSquare(2)}
                </div>
                <div className="board-row">
                    {this.renderSquare(3)}
                    {this.renderSquare(4)}
                    {this.renderSquare(5)}
                </div>
                <div className="board-row">
                    {this.renderSquare(6)}
                    {this.renderSquare(7)}
                    {this.renderSquare(8)}
                </div>
            </div>
        );
    }
}

class Game extends React.Component {
    constructor(props) {
        super(props);
        this.state = {
            history: [
                {
                    squares: new Array(9).fill(null)
                },
            ],
            stepNumber: 0,
            xIsNext: true,
        }
    }

    handleClick(i) {
        // const history = this.state.history
        // 如果我们“回到过去”，然后再走一步新棋子，原来的“未来”历史记录就不正确了，这个替换可以保证我们把这些“未来”的不正确的历史记录丢弃掉。
        const history = this.state.history.slice(0, this.state.stepNumber + 1)
        const current = history[history.length - 1]
        const squares = current.squares.slice()
        if (calculateWinner(squares) || squares[i]) {
            return
        }
        squares[i] = this.state.xIsNext ? 'x' : 'o'
        this.setState({
            // concat() 方法可能与你比较熟悉的 push() 方法不太一样，它并不会改变原数组，所以我们推荐使用 concat()。
            history: history.concat([{squares}]),
            stepNumber: history.length,
            xIsNext: !this.state.xIsNext
        })
    }

    jumpTo(step) {
        // 没有更新 state 中的 history 属性。这是因为 state 更新被合并了
        // React 不会更新 setState 方法中未提到的属性
        this.setState({
            stepNumber: step,
            xIsNext: step % 2 === 0
        })
    }

    render() {
        const history = this.state.history
        // const current = history[history.length - 1]
        const current = history[this.state.stepNumber]
        const winner = calculateWinner(current.squares)
        const moves = history.map((step, move) => {
            const desc = move ? `Go to move #${move}` : 'Go to game start'
            return (
                <li key={move}>
                    <button onClick={() => this.jumpTo(move)}>{desc}</button>
                </li>
            )
        })

        let status;
        if (winner) {
            status = 'Winner: ' + winner
        } else {
            status = `Next player: ${this.state.xIsNext ? 'x' : 'o'}`
        }

        return (
            <div className="game">
                <div className="game-board">
                    <Board
                        squares={current.squares}
                        onClick={(i) => this.handleClick(i)}
                    />
                </div>
                <div className="game-info">
                    <div>{status}</div>
                    <ol>{moves}</ol>
                </div>
            </div>
        );
    }
}

function calculateWinner(squares) {
    const lines = [
        [0, 1, 2],
        [3, 4, 5],
        [6, 7, 8],
        [0, 3, 6],
        [1, 4, 7],
        [2, 5, 8],
        [0, 4, 8],
        [2, 4, 6],
    ];
    for (let i = 0; i < lines.length; i++) {
        const [a, b, c] = lines[i];
        if (squares[a] && squares[a] === squares[b] && squares[a] === squares[c]) {
            return squares[a];
        }
    }
    return null;
}

// ========================================

const root = ReactDOM.createRoot(document.getElementById("root"));
root.render(<Game/>);
